282 research outputs found
Surface Plasmon Driven Electric and Magnetic Resonators for Metamaterials
Using interplay between surface plasmons and metamaterials, we propose a new
technique for novel metamaterial designs. We show that surface plasmons
existing on thin metal surfaces can be used to "drive" non-resonant structures
in their vicinity to provide new types of electric and magnetic resonators.
These resonators strictly adhere to surface plasmon dispersion of the host
metal film. The operating frequency of the resultant metamaterials can be
scaled to extremely high frequencies, otherwise not possible with conventional
split-ring-resonator-based designs. Our approach opens new possibilities for
theory and experiment in the interface of plasmonics and metamaterials to
harvest many potential applications of both fields combined.Comment: Less than 5 Journal Pages, 5 Figure
Negative Refraction Gives Rise to the Klein Paradox
Electromagnetic negative refraction in metamaterials has attracted
increasingly great interest, since its first experimental verification in 2001.
It potentially leads to the applications superior to conventional devices
including compact antennas for mobile stations, imaging beyond the diffraction
limit, and high-resolution radars, not to mention the anamolous wave
propagation in fundamental optics. Here, we report how metamaterials could be
used to simulate the "negative refraction of spin-zero particles interacting
with a strong potential barrier", which gives rise to the Klein paradox--a
counterintuitive relativistic process. We address the underlying physics of
analogous wave propagation behaviours in those two entirely different domains
of quantum and classical.Comment: 4 journal pages, 2 figure
Bulk Negative Index Photonic Metamaterials for Direct Laser Writing
We show the designs of one- and two-dimensional photonic negative index
metamaterials around telecom wavelengths. Designed bulk structures are
inherently connected, which render their fabrication feasible by direct laser
writing and chemical vapor deposition.Comment: 12 pages, 4 figures, submitted to Opt. Let
Recurrent N209* ABHD5 mutation in two unreported families with Chanarin Dorfman Syndrome
ABHD5 protein is widely involved in lipid and energy homeostasis. Mutations in the ABHD5 gene are associated with the onset of Neutral Lipid Storage Disease with Ichthyosis (NLSDI), historically known as Chanarin Dorfman Syndrome (CDS). CDS is a rare autosomal recessive lipid storage disease, characterized by non-bullous congenital ichthyosiform eritrhoderma (NCIE), hepatomegaly and liver steatosis. Myopathy, neurosensory hearing loss, cataracts, nystagmus, strabismus, and mental impairment are considered additional findings. To date, 151 CDS patients have been reported all over the world. Here we described two additional families with patients affected by CDS from Turkey. Our patients were a 42 and 22-years old men, admitted to the Hospital for congenital ichthyosis. Hepatic steatosis and myopathy were also detected in both patients. ABHD5 molecular analysis revealed the presence of N209* mutation. Our data enlarge the cohort of CDS patients and provide a revision of muscle clinical findings for this rare inborn error of neutral lipid metabolism
Validation of the EuroSCORE risk models in Turkish adult cardiac surgical population
Objective: The aim of this study was to validate additive and logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE) models on Turkish adult cardiac surgical population. Methods: TurkoSCORE project involves a reliable web-based database to build up Turkish risk stratification models. Current patient population consisted of 9443 adult patients who underwent cardiac surgery between 2005 and 2010. However, the additive and logistic EuroSCORE models were applied to only 8018 patients whose EuroSCORE determinants were complete. Observed and predicted mortalities were compared for low-, medium-, and high-risk groups. Results: The mean patient age was 59.5 years (±12.1 years) at the time of surgery, and 28.6% were female. There were significant differences (all p< 0.001) in the prevalence of recent myocardial infarction (23.5% vs 9.7%), moderate left ventricular function (29.9% vs 25.6%), unstable angina (9.8% vs 8.0%), chronic pulmonary disease (13.4% vs 3.9%), active endocarditis (3.2% vs 1.1%), critical preoperative state (9.0% vs 4.1%), surgery on thoracic aorta (3.7% vs 2.4%), extracardiac arteriopathy (8.6% vs 11.3%), previous cardiac surgery (4.1% vs 7.3%), and other than isolated coronary artery bypass graft (CABG; 23.0% vs 36.4%) between Turkish and European cardiac surgical populations, respectively. For the entire cohort, actual hospital mortality was 1.96% (n = 157; 95% confidence interval (CI), 1.70-2.32). However, additive predicted mortality was 2.98% (p< 0.001 vs observed; 95%CI, 2.90-3.00), and logistic predicted mortality was 3.17% (p< 0.001 vs observed; 95%CI, 3.03-3.21). The predictive performance of EuroSCORE models for the entire cohort was fair with 0.757 (95%CI, 0.717-0.797) AUC value (area under the receiver operating characteristic, AUC) for additive EuroSCORE, and 0.760 (95%CI, 0.721-0.800) AUC value for logistic EuroSCORE. Observed hospital mortality for isolated CABG was 1.23% (n = 75; 95%CI, 0.95-1.51) while additive and logistic predicted mortalities were 2.87% (95%CI, 2.82-2.93) and 2.89% (95%CI, 2.80-2.98), respectively. AUC values for the isolated CABG subset were 0.768 (95%CI, 0.707-0.830) and 0.766 (95%CI, 0.705-0.828) for additive and logistic EuroSCORE models. Conclusion: The original EuroSCORE risk models overestimated mortality at all risk subgroups in Turkish population. Remodeling strategies for EuroSCORE or creation of a new model is warranted for future studies in Turkey. © 2011 European Association for Cardio-Thoracic Surgery
A combined ULBP2 and SEMA5A expression signature as a prognostic and predictive biomarker for colon cancer
Background: Prognostic biomarkers for cancer have the power to change the course of disease if they add value beyond known prognostic factors, if they can help shape treatment protocols, and if they are reliable. The aim of this study was to identify such biomarkers for colon cancer and to understand the molecular mechanisms leading to prognostic stratifications based on these biomarkers. Methods and Findings: We used an in house R based script (SSAT) for the in silico discovery of stage-independent prognostic biomarkers using two cohorts, GSE17536 and GSE17537, that include 177 and 55 colon cancer patients, respectively. This identified 2 genes, ULBP2 and SEMA5A, which when used jointly, could distinguish patients with distinct prognosis. We validated our findings using a third cohort of 48 patients ex vivo. We find that in all cohorts, a combined ULBP2/SEMA5A classification (SU-GIB) can stratify distinct prognostic sub-groups with hazard ratios that range from 2.4 to 4.5 (p=0.01) when overall- or cancer-specific survival is used as an end-measure, independent of confounding prognostic parameters. In addition, our preliminary analyses suggest SU-GIB is comparable to Oncotype DX colon(®) in predicting recurrence in two different cohorts (HR: 1.5-2; p=0.02). SU-GIB has potential as a companion diagnostic for several drugs including the PI3K/mTOR inhibitor BEZ235, which are suitable for the treatment of patients within the bad prognosis group. We show that tumors from patients with worse prognosis have low EGFR autophosphorylation rates, but high caspase 7 activity, and show upregulation of pro-inflammatory cytokines that relate to a relatively mesenchymal phenotype. Conclusions: We describe two novel genes that can be used to prognosticate colon cancer and suggest approaches by which such tumors can be treated. We also describe molecular characteristics of tumors stratified by the SU-GIB signature. © Ivyspring International Publisher
Quality of life gains in frail and intermediate-fit patients with multiple Myeloma:Findings from the prospective HOVON123 clinical trial
Background: Frailty in newly-diagnosed multiple myeloma (NDMM) patients is associated with treatment-related toxicity, which negatively affects health-related quality of life (HRQoL). Currently, data on changes in HRQoL of frail and intermediate-fit MM patients during active treatment and post-treatment follow-up are absent. Methods: The HOVON123 study (NTR4244) was a phase II trial in which NDMM patients ≥ 75 years were treated with nine dose-adjusted cycles of Melphalan-Prednisone-Bortezomib (MPV). Two HRQoL instruments (EORTC QLQ-C30 and -MY20) were obtained before start of treatment, after 3 and 9 months of treatment and 6 and 12 months after treatment for patients who did not yet start second-line treatment. HRQoL changes and/or differences in frail and intermediate-fit patients (IMWG frailty score) were reported only when both statistically significant (p < 0.005) and clinically relevant (>MID). Results: 137 frail and 71 intermediate-fit patients were included in the analysis. Compliance was high and comparable in both groups. At baseline, frail patients reported lower global health status, lower physical functioning scores and more fatigue and pain compared to intermediate-fit patients. Both groups improved in global health status and future perspective; polyneuropathy complaints worsened over time. Frail patients improved over time in physical functioning, fatigue and pain. Improvement in global health status occurred earlier than in intermediate-fit patients. Conclusion: HRQoL improved during anti-myeloma treatment in both intermediate-fit and frail MM patients. In frail patients, improvement occurred faster and, in more domains, which was retained during follow-up. This implies that physicians should not withhold safe and effective therapies from frail patients in fear of HRQoL deterioration.</p
Quality of life gains in frail and intermediate-fit patients with multiple Myeloma:Findings from the prospective HOVON123 clinical trial
Background: Frailty in newly-diagnosed multiple myeloma (NDMM) patients is associated with treatment-related toxicity, which negatively affects health-related quality of life (HRQoL). Currently, data on changes in HRQoL of frail and intermediate-fit MM patients during active treatment and post-treatment follow-up are absent. Methods: The HOVON123 study (NTR4244) was a phase II trial in which NDMM patients ≥ 75 years were treated with nine dose-adjusted cycles of Melphalan-Prednisone-Bortezomib (MPV). Two HRQoL instruments (EORTC QLQ-C30 and -MY20) were obtained before start of treatment, after 3 and 9 months of treatment and 6 and 12 months after treatment for patients who did not yet start second-line treatment. HRQoL changes and/or differences in frail and intermediate-fit patients (IMWG frailty score) were reported only when both statistically significant (p < 0.005) and clinically relevant (>MID). Results: 137 frail and 71 intermediate-fit patients were included in the analysis. Compliance was high and comparable in both groups. At baseline, frail patients reported lower global health status, lower physical functioning scores and more fatigue and pain compared to intermediate-fit patients. Both groups improved in global health status and future perspective; polyneuropathy complaints worsened over time. Frail patients improved over time in physical functioning, fatigue and pain. Improvement in global health status occurred earlier than in intermediate-fit patients. Conclusion: HRQoL improved during anti-myeloma treatment in both intermediate-fit and frail MM patients. In frail patients, improvement occurred faster and, in more domains, which was retained during follow-up. This implies that physicians should not withhold safe and effective therapies from frail patients in fear of HRQoL deterioration.</p
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